When you visit a new Site of Grace for a third time in Elden Ring, you’ll be visited by Melina, a ghostly hooded Finger Maiden with a strange tattoo over her left eye. Melina will offer you an accord, whereby she will provide guidance and aid to you, the Tarnished. She tells you that you are Maiden-less and that she can pay the role of Maiden for you, which means she can turn Runes into strength. You’re then given a choice to either accept her offer, or refuse it.
You should definitely accept Melina in Elden Ring. The main reason you should do this is that she’s basically the only way you can level up your character. When she says she turns Runes into strength, she means she can increase your attributes in return for Runes, and every time you increase an attribute in Elden Ring, you level up your character.
If you accept Melina, she will also give you the Spectral Steed Whistle ring, which is a vitally important tool that enables you to summon Torrent, your horse, and getting around the Lands Between will be a slow process without a mount. If you refuse Melina, you don’t get any of these things, but you will get the opportunity to accept her again next time you visit a Site of Grace. We’re not even sure why you get the option to refuse her. You’d only do so if you wanted to make an already difficult game even harder.